Klas, profesor, koledzh: one consonant instead of two

Borrowed words give up their double consonants at the border: where English writes two letters, Ukrainian writes one. Klas, kasa, masa, profesor, koledzh, atestat, hryp, baroko, suma, grupa, plastmasa, komisiia. For example: “Професор читає лекцію в аудиторії” — The professor is giving a lecture in the lecture hall. A rule from the Ukrainian course: worked out on examples, not memorized as a wording.

Updated September 1, 2026 · Lingofly

How it works

Borrowed words give up their double consonants at the border: where English writes two letters, Ukrainian writes one. Klas, kasa, masa, profesor, koledzh, atestat, hryp, baroko, suma, grupa, plastmasa, komisiia.

The exceptions are proper names and a few settled words: vanna, manna, Holandiia, Nitsa.

Native words are the opposite: there double consonants are alive and required. The parts of the word genuinely meet: zannia, zhyttia, pytannia, viddilennia, ozdoblemnia.

Two more habits of the same border. Greek and Latin words keep their i as i: istoriia, himnaziia, informatyka, dystsyplina, fizyka. And where other alphabets keep a special letter for the other e sound, Ukrainian does not. Plain e writes it: ekzamen, etap, efekt, epokha.

Table

Klas, profesor, koledzh: one consonant instead of two
with doublesin Ukrainianwhat changed
classklasa single s
professorprofesora single s
historyistoriiathe i of Latin roots
effectefektplain e, one f
knowledgezanniaa native nn stays

By example

  • Професор читає лекцію в аудиторії
    The professor is giving a lecture in the lecture hall
  • Наш клас складається з двадцяти учнів
    Our class has twenty students
  • Іспит з інформатики буде у червні
    The computer science exam is in June

How the rule settles in your head

A rule is not memorized from an explanation. It is memorized from an attempt to use it and a mistake — that is why the app delivers it mixed in with words, not as a separate lesson: it resurfaces exactly where you forgot it.

Frequently asked

Why it is klas and profesor, one s each?

Borrowed words give up their double consonants at the border: where English writes two letters, Ukrainian writes one. Klas, kasa, masa, profesor, koledzh, atestat, hryp, baroko, suma, grupa, plastmasa, komisiia.

What does it look like in an example sentence Ukrainian?

“Професор читає лекцію в аудиторії” — The professor is giving a lecture in the lecture hall. A rule is easier to test on sentences like this than to memorize as a wording: what surfaces in conversation is the sentence.

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Test the rule on examplesPractice